What is "trial by combat"

Trial by combat (also wager of battle, trial by battle or judicial duel) was a method of Germanic law to settle accusations in the absence of witnesses or a confession in which two parties in dispute fought in single combat; the winner of the fight was proclaimed to be right. In essence, it was a judicially sanctioned duel. It remained in use throughout the European Middle Ages, gradually disappearing in the course of the 16th century.

Trial by Combat (US title: Dirty Knights' Work) is a 1976 film directed by Kevin Connor. It stars John Mills and Donald Pleasence.